Storage battery.



. entra n stares ATNTT ornin.

mo s A. unison, .or LLEW'ELLYN' PARK, .oiaAneE, NEW JERSEY, ASSIGNOR TOEDISO1\I sronAen BATTERY COMPANY, OF

PORATION OF NEW JERSEY.

Wns'r OR NGE, NEW JERSEY, A COB- 'sroRAeE BATTERY.

No Drawing.

To all whom it mag/concern:

Beit known that I, Tnonas ALVA EDISON, ya citizen of the United States,residing at Llewellyn Park, Orange, county of Essex, 5 and State-of'NewJersey, have in ented certain new and useful Improvements in Storm ageBatteries,

description.

Y -In LettersPatent of the United States No, 873,220, dated December 10,1007, I. de- Scribe certainimprovements instorage batteries, usingalkaline electrolytes :with an of which the following is t oxygencompound of nickel as theactive depolarizing material, and in which anoxygen compound of bismuth is added to the nickel mass, so as to resultin a substantial increase in the capacity. I suggest in said patent theadmixture 'of the two oxygen compounds by .pre cipitating them fromtheir dissolved fsalts. I My present invention relates to an improvedprocess by means of which the oxygen compound of bismuth can be moreeffectively added to-the nickel mass and the addition can .be underbetter control than by the specific practice suggested in my saidpatent. *Also, my present method can be practiced for the addition ofthe oxygen compound of bismuth after the individual electrode elementshave been formed, and indeed, after they have been assembled in theusual plates orgrids. Ordinarily, however, I prefer to carry ontheprocess in connec: tion with the active material before the latter isintroduced 'within the containing pockets-since it is possible inthisway to perform the process more economically and on alargecommercial scale.

In carrying the invention into eflect, and

' 40 assuming that the process is ,toxbe utilized commercially inconnection with the manufacture of' the depolarizing material before thelatter is introduced within the receiving pockets, I proceedsubstantially sfollows 4,5,.73lickelhydroxid obtained in any suitableway, is first crushed into small granules, so

' that the whole mass will 'pass 'a 20 mesh screen To asutlicient'quantity of this materlal, I, now add a concentrated solutionof a bisnntth salt, dissolved ina suitable solvent.

On'e' example of such a solution" is tri-eh'lorid (of, bismuth dissolvedin a strong aqueous oXid or hydroxid thereof. caust1c solutlon. is drawnoff,- and the result- Specifi ation oflett r P n Patented Jan. 18,1910.Applicatibn filed March 23, 1908. Serial No. 42 21574.-

I example is tri-chlorid of bismuth dissolved to saturation in .acetone.By varying the proportion of bismuth saltused, the aniount of bismuthadded to the active material may be readily and accurately Enough of thesolution is added to cover the nickel hydroxid mass, which is allowed tosoak for several hours in the solution until controlled.

the pores of thc hydroxid particles become. 7

saturated therewith. The solution is now drawn ofi", and the wet massofactive mateto'a considerable excess ofa 10% solutionof potassic 'orsodium hydrate, which is The mass is now then heated for several hoursnear the boil% ing point, and for about thirty minutes at the boilingpoint.

As a result of this action, the bismuth salt will be converted to theAfterward, the

ing mass is successively washedwith warm 'water untilthe alkali-iswashedout, after which the mass is driedand is ready to be used in connectionwith the make-up 'of the electrodes in any suitable way.

Storage batteries.,\e11iployi11 nickel hydroxid', the particles of whichcontain in their pores bismuth oxid or'hydroxid,as explained, will-notdeteriorate in capacity to the same extent over longperiods oftime, aswhen nickel hydroxid alone is used. By employing in the electrolyte, asmall percentage of lithium"hydro'Xid, as'I describe in Letters Patentdated January 14, 1908 and numbered 876,445, the; capacity of thebattery is very greatly increased, especially when used inbadly-"ventilated places, in which the temperature of the cells isunduly raised. I am, still unable to explain the reason for the superiorresults Whiclrare secured when bismuth oxid or hydroxid employed inconnection with the active nickel mass and when lithium hydroxid is,used in the electrolyte,rbut the .fact remains that, as a result ofactual test and ob servation, the advantages pointed out are se cured.

' solution of chlorid ofannnonia, a'ndanother llllhilel nickel hydroxidfinally washed free of in mass, as explained, so that the bismuth willbe absorbed in its pores before the active'material is introduced intothe electrode elements, it will be understood that the tubes or pocketsor other supports for the nickelhydroxid may be first filled with thesame, and if desired, the tubes or pockets may be actually mounted inthe supporting plates, which may be then soaked in the his muthsolution, after which the electrode elements so treated may be dried,heated in a caustic alkali solution, as explained, and

the alkali.

In some respects, the addition of bismuth, as explained, may beadvantageously ef- 'fected inconnection with the active iron mass on thenegative electrode, this being especially true when mercury. is usedthere'- with, since a bismuth amalgam will be formed, which possessessome advantages over mercury alone in constituting a continuous net workof conductors extending in all directions through the mass. In anapplication filed concurrently. herewith, I describe my improved processas carried out for this purpose. In the present case, I propose to claimthe improved nickel mass resulting from the treatment described, and toclaim the process broadly as applied to the treatment of the active massof an alka line storage battery, including in that expression, theactive material on either electrode. l n my concurrent application, Ipropose to claim the specific process of adding bismuth to the activematerial. by subjecting one or more electrode plates containing theactive material to the process described, and to'claim the improved ironmass containing bismuth.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent as follows l. The process of impregnating amass of active material for alkaline storage batteries With an oxygencompound of bismuth, which consists in soaking the active mass in asolution of a bismuth salt, and in heating the mass as so treated in'acaustic alkali solution, substantially as set forth.

2. The process of impregnating a mass of active material for alkalinestorage batteries with an oxygen compound of bismuth, which consists insoaking the active mass in a solu'-.

tion of bismuth salt, in drying the mass, and in then heating it in acaustic alkali solution, substantially as and for the purposesset forth.

3. The process of impregnating a mass of active material for alkalinestorage batteries, With an oxygen compound of bismuth, which consists insoaking the active mass in a solution of bismuth salt, in dryin themass, in then heating it in a caustic al and in finally Washing the massso treated, substantially as set forth.

at. The process of impregnating a mass of active material for alkalinestorage batteries, with an oxygen compound of bismuth,which consists insoaking the active mass in a solution of bismuth salt, in centrifugingthe mass, in then heatin it in a caustic" alkali solution, and in finaly washing the in'ass to remove the alkali,

5. The process of impregnating a. mass of active material for alkalinestorage batteries with an oxygen compound of bismuth, Which consists insoaking the active mass in a solu- .tion of a bismuth salt, incentrifuging the mass, in then drying it, in then heating the dried massin a caustic alkali solution, and in finally washing the mass .to removethe alkali, substantially as set forth.

(3. Theprocess of impregnating a mass of active material for alkalinestorage batteries with an oxygen compound of bismuth vhich consists insoaking the active mass. in a solution of tri-chlorid of bismuth, and inheating the mass in a caustic alkali. solution, substantially as setforth.

7. The process of 1m )regnatmg a mass of active material for alka inestorage batteries with an oxygen com mind of bismuth, which consists insoaking t e active mass in a solution of tri-chlorid of bismuth inacetone, and in heating the mass in a caustic alkali solution,substantially as set forth.

This specification signed and witnessed this 13th day of March 1908.

. THOS. A. EDISON. lVitnesses ANNA R'Kmnru, ll. ll. DYKE.

ali solution,

substantially as set forth.

